Returns the type of calculation used to determine the displayed value of a data field. The available types are determined by ShowValueAs.ShowValueAsType.

 public ShowValueAsType ValueType{ get; }
Public Property ValueType() As ShowValueAsType

Value fields always return ShowValueAsType.Normal. You can check if a Pivot Table field is a value field with the IsValuesLabel Property

This is set using SetShowValueAs().
When calling SetShowValueAs(), certain ShowValueAsTypes use a source field as a base field and an index for one of the values in the data source column associated with the source field.